Paracetamol for the management of pain in inflammatory arthritis: a systematic literature review.

OBJECTIVE To systematically review the literature on the efficacy and safety of paracetamol (acetaminophen) in the management of pain in inflammatory arthritis. METHODS A systematic search was performed in Medline, Embase, the Cochrane Library, and 2008/2009 American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) conference abstracts for clinical trials and observational studies of paracetamol in patients with inflammatory arthritis. Included trials were appraised for risk of bias, and relevant study details were abstracted. Efficacy was assessed from clinical trials using improvement in pain as the outcome measure, and safety was assessed using total adverse events and withdrawals due to adverse events as outcome measures. Safety data from observational studies were assessed separately. RESULTS Eleven articles containing 12 clinical trials and 1 observational study were identified, all in patients with rheumatoid arthritis. The trials were of short duration, used atypical doses of paracetamol, and all had a high risk of bias. Overall, there was weak evidence of a benefit of paracetamol over placebo and an additive benefit of paracetamol in combination with nonsteroidal antiinflammatory drugs (NSAID). The benefit of paracetamol to NSAID alone was uncertain. No significant differences in safety were seen in the limited clinical trial data. One cohort study showed an increased rate of serious gastrointestinal events with paracetamol over NSAID when used concurrently with corticosteroids and other analgesics, but had significant methodological limitations. CONCLUSION There is weak evidence for the efficacy of paracetamol in patients with inflammatory arthritis, and insufficient disease-specific safety data to draw conclusions.